JP2016079949A - Saddle-riding type vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce heat quantity transmitted from an engine to an intake flow rate adjustment device through an intake member.SOLUTION: A saddle-riding type vehicle includes: an engine; an intake flow rate adjustment device adjusting a flow rate of intake suctioned to the engine; and a resin-based intake member 50 having an inner wall 51 forming a flow passage 54 guiding intake from the intake flow rate adjustment device to the engine. A center line 70 of the intake member 50 has a first circular arc part 71 and a second circular part 72 continued to each other. A first curvature center 71a of the first circular arc part 71 and a second curvature center 72a of the second circular arc part 72 are deviated from each other.SELECTED DRAWING: Figure 10

Description

  The present invention relates to a saddle riding type vehicle.

  Patent Document 1 discloses a straddle-type vehicle including an intake member that connects an engine and a throttle body.

JP 2013-227967 A

When electronic parts such as a throttle opening sensor are attached to the throttle body, it is desirable to reduce the amount of heat transferred from the engine to the throttle body in order to suppress the temperature rise of the electronic parts.
If the intake member is made of resin, heat transfer from the engine to the throttle body is suppressed as compared with the case where the intake member is made of metal. However, even if the intake member is made of resin, heat transfer from the engine to the throttle body is not completely cut off. Therefore, there is a case where it is desired to further reduce the amount of heat transmitted to the throttle body.

  Accordingly, one of the objects of the present invention is to provide a straddle-type vehicle that can reduce the amount of heat transfer from the engine to the intake flow rate adjusting device.

  One embodiment of the present invention is a resin product including an engine, an intake flow rate adjustment device that adjusts the flow rate of intake air sucked into the engine, and an inner wall that forms a flow path that guides intake air from the intake flow rate adjustment device to the engine A straddle-type vehicle is provided. The center line of the intake member includes a first arc portion and a second arc portion that are continuous with each other. The first curvature center of the first arc portion and the second curvature center of the second arc portion are at different positions.

  According to this configuration, since the intake member is made of a resin having a lower thermal conductivity than metal, it is difficult for the heat of the engine to be transmitted to the intake flow rate adjusting device via the intake member. Furthermore, since the center line of the intake member has the first arc portion and the second arc portion, the heat transfer distance of the intake member is greater than when the entire center line of the intake member is a straight line. Thus, since the heat conductivity of the intake member is low and the heat transfer distance of the intake member is large, the heat transfer amount from the engine to the intake flow rate adjusting device can be further reduced.

  In the present embodiment, the first arc portion, the first center of curvature, the second arc portion, and the second curvature center may all be on the same plane. In this case, the amount of heat transfer can be reduced while ensuring good manufacturability. In the configuration described above, a line segment in which the first center of curvature and the second center of curvature are arranged at both ends may intersect a center line of the intake member, or intersect a center line of the intake member. It does not have to be.

When the line segment intersects the center line of the intake member, the difference in the heat transfer distance can be reduced on the same plane. Specifically, as compared with the case where the center line of the intake member is C-shaped, transmission of two portions (part of the inner wall of the intake member) arranged on both sides of the center line of the intake member in the plane is described. The difference in thermal distance can be reduced.
When the line segment does not intersect the center line of the intake member, the heat transfer distance of a specific portion in the circumferential direction can be made longer or shorter than the heat transfer distance of other portions. In other words, the heat transfer distance at an arbitrary position in the circumferential direction can be adjusted. For example, when the electronic component is attached to only a part of the air intake member in the circumferential direction, the heat transfer distance of the specific part to which the electronic component is attached can be increased to suppress heat transfer to the electronic component.

In the present embodiment, the first arc portion and the first center of curvature may be arranged on a plane different from the plane including the second arc portion and the second center of curvature. In this case, the heat transfer distance of the specific part in the circumferential direction can be made longer or shorter than the heat transfer distance of the other parts.
In this embodiment, the curvature radius of the first arc portion and the curvature radius of the second arc portion may be different from each other or may be equal to each other. When the curvature radii of the first arc portion and the second arc portion are different from each other, the amount of heat transfer can be reduced while flexibly corresponding to the layout of members around the intake member. When the curvature radii of the first arc portion and the second arc portion are equal to each other, the amount of heat transfer can be reduced while ensuring good manufacturability.

In the present embodiment, the intake member may include an outer wall formed with an inlet for guiding the intake air that has passed through the intake air flow adjusting device to the flow path and an outlet for discharging the intake air that has flowed into the inlet. Good. When the inlet is viewed from the intake flow rate adjusting device, at least a part of the outlet may be visible.
According to this configuration, at least part of the outlet of the intake member can be seen from the inlet of the intake member even though the flow path of the intake member is curved. That is, the amount of heat transfer can be reduced even with a simple shape or a relatively short shape in which at least a part of the outlet can be seen.

In the present embodiment, the intake member may further include a flange formed at an end of the flow path. According to this configuration, since the heat radiation area of the intake member is increased as compared with the case where no flange is provided, the amount of heat transmitted from the engine to the intake flow rate adjusting device via the intake member can be reduced.
In the present embodiment, the straddle-type vehicle may further include a seal made of an elastic material interposed between the engine or the intake air flow adjusting device and the intake member. The seal may be annular or plate-shaped.

According to this configuration, the seal is made of an elastic material having a thermal conductivity lower than that of the metal. The seal is interposed between the engine or the intake flow rate adjusting device and the intake member. Therefore, the heat transfer amount from the engine to the intake air flow rate adjusting device can be further reduced.
In the present embodiment, the inner wall of the intake member includes an upstream wall portion extending in the axial direction of the intake member and a downstream wall extending in the axial direction of the intake member at a position downstream of the upstream wall portion in the flow of intake air. An annular step may be formed that includes a connection portion and a connection wall portion that connects the first connection end of the upstream wall portion and the second connection end of the downstream wall portion. The second connection end of the downstream wall portion may be disposed outside the first connection end of the upstream wall portion in the radial direction of the intake member. In this case, the connection wall portion extends radially outward of the intake member from the first connection end toward the second connection end.

  According to this configuration, the annular step is formed on the inner wall of the intake member. The connection wall portion connects the first connection end of the upstream wall portion and the second connection end of the downstream wall portion to each other. The second connection end of the downstream wall portion is disposed outward of the first connection end of the upstream wall portion in the radial direction of the intake member at any position in the circumferential direction of the intake member. The connecting wall portion faces downstream of the intake air flow.

  When the connecting wall faces upstream of the intake air flow, the fuel contained in the air-fuel mixture that has flowed back to the intake member due to the pulsation of the engine gradually accumulates at the step of the intake member, and the fuel droplets accumulated at the step It is sucked into the engine at an unexpected timing. In this case, more fuel than the intended amount is supplied to the engine. Therefore, the amount of the fuel staying in the intake member can be reduced by directing the connection wall portion upstream over the entire circumference.

In the present embodiment, the engine may be an air-cooled engine. Air-cooled engines are more likely to rise in temperature than water-cooled engines. Therefore, by attaching the intake member according to the present embodiment to such an engine, the amount of heat transferred from the engine to the intake flow rate adjusting device can be effectively reduced.
In the present embodiment, the engine may be a single cylinder engine. If the displacement is the same, the single-cylinder engine is often smaller and has a smaller heat radiation area than the multi-cylinder engine. Therefore, when generating the same output, the temperature of the single cylinder engine is more likely to rise than that of the multi-cylinder engine. By attaching the intake member according to the present embodiment to such an engine, the amount of heat transfer from the engine to the intake flow rate adjusting device can be effectively reduced.

In another embodiment of the present invention, the manufacture of an intake member that manufactures a resin intake member including an inner wall that forms a flow path that guides intake air to the engine from an intake air flow adjustment device that adjusts the flow rate of intake air sucked into the engine. Provide a method.
In the manufacturing method of the intake member, the mold and the first rotating core are in contact with the first end of the arc-shaped first rotating core and the second end of the arc-shaped second rotating core. A step of forming a resin injection space between the core and the second rotary core, a step of injecting resin into the resin injection space to mold the suction member, and the first rotary core and the second rotary core Removing the first rotating core and the second rotating core from the intake member by rotating the child. The center line of the intake member includes a first arc portion and a second arc portion that are continuous with each other. The first curvature center of the first arc portion and the second curvature center of the second arc portion are at different positions.

  According to this method, since the resin intake member whose center line has the first arc portion and the second arc portion can be manufactured, the amount of heat transfer from the engine to the intake flow rate adjusting device can be further reduced.

It is a schematic diagram which shows the left side surface of the saddle riding type vehicle according to the first embodiment of the present invention. It is a schematic diagram which shows the left side surface of the saddle riding type vehicle from which an exterior cover and the like are removed. It is a schematic diagram which shows the outline of an engine and the structure relevant to this. It is a figure which shows the external appearance of an intake member. It is the figure which looked at the intake member from the direction of arrow V shown in FIG. It is the figure which looked at the intake member from the direction of the intake air flow adjusting device. It is the figure which looked at the intake member from the direction of the engine. It is a figure which shows the cross section of the intake member which follows the VIII-VIII line shown in FIG. It is a figure which shows the cross section of the intake member which follows the IX-IX line shown in FIG. It is a figure which shows the cross section of the intake member which follows the XX line shown in FIG. It is a schematic diagram which shows the cross section of the level | step difference of an intake member. It is a schematic diagram which shows the cross section of the metal mold | die apparatus for shape | molding an intake member. It is a figure which shows the cross section of the metal mold apparatus which follows the XIII-XIII line | wire shown in FIG. It is a schematic diagram which shows the cross section of the metal mold | die apparatus when shape | molding the suction member. It is a schematic diagram which shows the cross section of the metal mold | die apparatus when the core is removed from the intake member. It is a figure which shows the centerline of the intake member which concerns on other embodiment of this invention, and when the flow path of an intake member is twisted, the 1st circular arc part, the 1st curvature center, the 2nd circular arc part, and the 2nd curvature The center positional relationship is shown. It is the figure which looked at the 1st curvature center and the 2nd curvature center from the direction of arrow XVII shown in FIG. It is a figure which shows the cross section of the intake member which concerns on other embodiment of this invention. It is a schematic diagram which shows the outline of the fuel supply apparatus which concerns on further another embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
In the following description, the front, rear, top and bottom and left and right directions are in a reference posture corresponding to a state in which the saddle riding type vehicle 1 travels straight on a horizontal plane (a state in which the steering handle 7 is in a straight travel position), and the driver Based on the driver's viewpoint when is facing forward. The left-right direction corresponds to the vehicle width direction. The vehicle center corresponds to a vertical plane that passes through the center line of the head pipe 3 and is orthogonal to the rotation center of the rear wheel Wr. Hereinafter, unless otherwise specified, the straddle-type vehicle 1 in the reference posture will be described.

FIG. 1 is a schematic diagram showing a left side surface of a saddle riding type vehicle 1 according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing the left side surface of the saddle riding type vehicle 1 with the exterior cover 14 and the like removed.
As shown in FIG. 1, the saddle riding type vehicle 1 includes a frame 2 covered with an exterior cover 14. The frame 2 includes a head pipe 3 extending rearward and upward, a main frame 4 extending rearward and downward from the head pipe 3, and a pair of left and right seat frames 5 extending rearward and upward from the main frame 4. The pair of seat frames 5 are respectively arranged on the right side and the left side of the vehicle center.

  As shown in FIG. 2, the saddle-ride type vehicle 1 includes a front fork 6 that is rotatably supported around the center line of the head pipe 3, a front wheel Wf that is rotatably supported by the front fork 6, A steering handle 7 that rotates left and right around the center line of the head pipe 3 together with the front fork 6 and the front wheel Wf is included. The steering handle 7 includes a handle bar 7 a disposed above the head pipe 3. The handle bar 7 a is disposed at a position above the seat 11 and ahead of the seat 11. When the steering handle 7 is operated by the driver, both the front wheels Wf rotate left and right with respect to the steering handle 7. Thereby, the saddle riding type vehicle 1 is steered.

  As shown in FIG. 1, the saddle riding type vehicle 1 includes a swing arm 9 that is supported by a frame 2 so as to be swingable in a vertical direction, and a rear wheel Wr that is rotatably supported by a rear end portion of the swing arm 9. including. The straddle-type vehicle 1 further includes an engine 8 that generates power for driving the straddle-type vehicle 1, and a drive mechanism (not shown) that transmits the power of the engine 8 to the rear wheels Wr. The engine 8 is disposed below the main frame 4. The engine 8 is fixed to the frame 2. The swing arm 9 and the rear wheel Wr can swing up and down around the front end of the swing arm 9. The rear wheel Wr is disposed behind the engine 8 and below the seat frame 5 in a side view.

  As shown in FIG. 1, the saddle riding type vehicle 1 includes a saddle type seat 11 on which a driver sits. The seat 11 may be for single passengers or for two passengers. FIG. 1 shows an example in which a seat 11 of a driver on which a driver sits and a passenger's seat 11b on which a passenger sits are provided on a seat 11. The seat 11 is disposed behind the head pipe 3. The seat 11 is disposed above the pair of seat frames 5. The seat 11 is disposed above the engine 8. The seat 11 may be supported by the pair of seat frames 5 through other members such as a storage box 12 described later, or may be directly supported by the pair of seat frames 5.

  As shown in FIG. 2, the saddle riding type vehicle 1 includes a storage box 12 having an opening at an upper end portion, and a fuel tank 13 for storing fuel supplied to the engine 8. The storage box 12 is disposed in front of the fuel tank 13. The pair of seat frames 5 are disposed on the right and left sides of the storage box 12. The storage box 12 and the fuel tank 13 are supported by the frame 2. The storage box 12 and the fuel tank 13 are disposed below the seat 11. The front end portion of the seat 11 is rotatably connected to the front end portion of the storage box 12 around a horizontal opening / closing axis extending in the vehicle width direction. The sheet 11 can be turned up and down with respect to the storage box 12. The opening of the storage box 12 is opened and closed by the sheet 11.

  As shown in FIG. 1, the saddle riding type vehicle 1 includes an exterior cover 14 that covers the frame 2 and the like. The exterior cover 14 has a recess 14 a that is recessed below the seat 11 between the seat 11 and the steering handle 7. The bottom of the recess 14 a is disposed above the main frame 4. The exterior cover 14 includes a front fender 15 disposed above and behind the front wheel Wf, a front cover 16 that covers the head pipe 3 from the front thereof, and a leg shield 17 disposed behind the head pipe 3 and the front cover 16. including. The right end and the left end of the leg shield 17 are arranged in front of the left and right feet of the driver. The exterior cover 14 further includes a rear cover 18 that covers the pair of seat frames 5 from the sides, and a rear fender 19 that is disposed above and behind the rear wheel Wr.

FIG. 3 is a schematic diagram showing an outline of the engine 8 and a configuration related thereto. Note that the arrangement, posture, size, and the like of each member shown in FIG. 3 are different from the actual arrangement.
The engine 8 is, for example, an air-cooled four-stroke single cylinder engine. As shown in FIG. 3, the engine 8 includes a crankshaft 24 that can rotate around the crankshaft axis Ac, a piston 22 that reciprocates in the cylinder 21 according to the rotation of the crankshaft 24, and the piston 22 connected to the crankshaft 24. And a connecting rod 23. The engine 8 further houses a cylinder body 26 that forms a cylinder 21 that houses the piston 22, a cylinder head 25 that forms a combustion chamber 28, an intake port 29, and an exhaust port 30, and a crankshaft 24 together with the cylinder body 26. And a crankcase 27.

  As shown in FIG. 2, the cylinder head 25 is disposed in front of the cylinder body 26. The intake port 29 extends upward from the combustion chamber 28, and the exhaust port 30 extends downward from the combustion chamber 28. The cylinder 21 extends in the front-rear direction in plan view. The cylinder 21 is inclined in the vertical direction so as to be positioned upward as it approaches the front end of the cylinder 21. The crankcase 27 is disposed behind the cylinder body 26. The crank axis Ac extends in the left-right direction.

  As shown in FIG. 3, the engine 8 includes an ignition plug 31 that burns a mixture of air and fuel in the combustion chamber 28, an intake valve 32 that opens and closes the intake port 29, and an exhaust valve 33 that opens and closes the exhaust port 30. Including. The combustion chamber 28 is connected to an intake passage 34 that guides intake air to the combustion chamber 28, and an exhaust passage 35 that discharges exhaust gas generated in the combustion chamber 28 during combustion. The intake port 29 is a part of the intake passage 34, and the exhaust port 30 is a part of the exhaust passage 35.

  As shown in FIG. 3, the saddle riding type vehicle 1 includes an air filter 36 that removes foreign matter from the intake air flowing through the intake passage 34 toward the combustion chamber 28, and an intake air that changes the flow rate of the intake air supplied to the combustion chamber 28. And a flow rate adjusting device 38. The air filter 36 is accommodated in an air cleaner box 37. The intake air flow adjustment device 38 includes a throttle valve 39 disposed in the intake passage 34 and a throttle body 40 that accommodates the throttle valve 39. The air cleaner box 37 and the throttle body 40 form a part of the intake passage 34.

  As shown in FIG. 3, an example of the throttle valve 39 is a butterfly valve. The throttle valve 39 is driven with a movement amount corresponding to the operation amount of the accelerator grip 7b attached to the right end portion of the handle bar 7a. The throttle valve 39 may be connected to the accelerator grip 7b via a throttle wire, or may be connected to a throttle motor that is driven in accordance with the operation of the accelerator grip 7b. As shown in FIG. 2, the throttle body 40 is disposed at a height between the main frame 4 and the cylinder head 25. The throttle body 40 is connected to the cylinder head 25 via an intake member 50 that forms a part of the intake passage 34. The intake member 50 extends upward from the cylinder head 25 toward the throttle body 40.

  As shown in FIG. 3, the saddle riding type vehicle 1 includes a fuel supply device 43 that supplies fuel to the combustion chamber 28. The fuel supply device 43 includes the above-described fuel tank 13, a fuel injector 44 (fuel injector) that injects fuel sent from the fuel tank 13, and a fuel pump 45 that sends fuel in the fuel tank 13 to the fuel injector 44. And a fuel pipe 46 that guides fuel from the fuel pump 45 to the fuel injector 44. The fuel injector 44 may inject fuel toward the intake passage 34 or may inject fuel toward the combustion chamber 28. FIG. 2 shows an example in which the fuel injector 44 injects fuel toward the intake passage 34. The fuel injector 44 is attached to the intake member 50.

  As shown in FIG. 3, the saddle riding type vehicle 1 includes an ECU 47 (Electronic Control Unit) that controls the engine 8. The ECU 47 is connected to a plurality of sensors including a throttle opening sensor 48 that detects the position of the throttle valve 39 and a crank sensor 49 that detects the rotational speed of the crankshaft 24. The throttle opening sensor 48 is attached to the intake flow rate adjusting device 38, and the crank sensor 49 is attached to the engine 8. The ECU 47 controls the fuel injection amount from the fuel injector 44, the ignition timing of the spark plug 31, and the like based on the detection values of these sensors.

Next, the structure and manufacturing method of the intake member 50 will be described in detail. First, the structure of the intake member 50 will be described with reference to FIGS. 4 to 11, and then the manufacturing method of the intake member 50 will be described with reference to FIGS. 12 to 15.
In the following description, the axial direction Da (see FIG. 11) is a direction along the center line 70 of the intake member 50, the circumferential direction Dc is a direction around the center line 70 of the intake member 50, and the radial direction Dr is The direction is perpendicular to the center line 70 of the intake member 50. As shown in FIG. 10, since the center line 70 of the intake member 50 is not a straight line, the axial direction Da changes according to the position of the center line 70. Similarly, the circumferential direction Dc and the radial direction Dr change according to the position of the center line 70.

  As shown in FIG. 10, the intake member 50 is made of synthetic resin. The inner wall 51 of the intake member 50 forms a flow path 54 for guiding intake air from the intake flow rate adjusting device 38 to the engine 8 by a cylindrical inner wall surface. The flow path 54 is a part of the intake passage 34. An inlet 53 corresponding to the upstream end of the flow path 54 and an outlet 55 corresponding to the downstream end of the flow path 54 are opened at the outer wall 52 of the intake member 50.

  As shown in FIG. 10, the inlet 53 of the channel 54 is disposed above the outlet 55 of the channel 54. The intake air that has flowed into the flow path 54 from the inlet 53 of the flow path 54 is discharged out of the flow path 54 from the outlet 55 of the flow path 54. As shown in FIGS. 6 and 7, the inlet 53 and the outlet 55 of the channel 54 are both circular, for example. The diameter of the outlet 55 of the channel 54 is smaller than the diameter of the inlet 53 of the channel 54. Therefore, the opening area of the outlet 55 of the channel 54 is smaller than the opening area of the inlet 53 of the channel 54.

As shown in FIGS. 4 and 5, the intake member 50 includes an annular first flange portion 56 coupled to the throttle body 40, an annular second flange portion 58 coupled to the cylinder head 25, and a first flange. And a cylindrical portion 57 extending from the portion 56 to the second flange portion 58. The first flange portion 56 and the second flange portion 58 are connected to each other by a cylindrical portion 57.
As shown in FIGS. 4 and 5, the first flange portion 56 includes a flat first mounting surface 56a, and the second flange portion 58 includes a flat second mounting surface 58a. The first mounting surface 56a is inclined with respect to the second mounting surface 58a. The inlet 53 of the flow channel 54 is opened at the first mounting surface 56a of the first flange portion 56, and the outlet 55 of the flow channel 54 is opened at the second mounting surface 58a of the second flange. As shown in FIG. 6, when the inlet 53 is viewed in the direction perpendicular to the first mounting surface 56 a of the first flange portion 56 from the intake flow rate adjusting device 38, a part of the outlet 55 can be seen.

  As shown in FIG. 8, the first flange portion 56 is connected to the throttle body 40 by a plurality of bolts BT. A metal bush B1 (bushing) into which the bolt BT is inserted is held in a first bolt insertion hole 56b that penetrates the first flange portion 56 in the thickness direction. The first mounting surface 56 a of the first flange portion 56 faces the end surface of the throttle body 40 in parallel. The first flange portion 56 is connected to the throttle body 40 by a plurality of bolts BT in a state where the annular first seal 61 is interposed between the first mounting surface 56a of the first flange portion 56 and the end surface of the throttle body 40. Is done. Accordingly, the gap between the first flange portion 56 and the throttle body 40 is closed by the first seal 61.

  As shown in FIG. 9, the second flange portion 58 is connected to the cylinder head 25 by a plurality of bolts BT. The metal bush B1 into which the bolt BT is inserted is held in a second bolt insertion hole 58b that penetrates the second flange portion 58 in the thickness direction. The second mounting surface 58 a of the second flange portion 58 faces the end surface of the cylinder head 25 in parallel. The second flange portion 58 is connected to the cylinder head 25 by a plurality of bolts BT in a state where the annular second seal 62 is interposed between the second mounting surface 58a of the second flange portion 58 and the end surface of the cylinder head 25. Is done. As a result, the gap between the second flange portion 58 and the cylinder head 25 is closed by the second seal 62.

  Both the first seal 61 and the second seal 62 are made of an elastic material such as synthetic resin or rubber. As shown in FIG. 8, the first seal 61 is held in an annular first seal holding groove 63 provided in the throttle body 40. As shown in FIG. 9, the second seal 62 is held in an annular second seal holding groove 64 provided on the second mounting surface 58 a of the second flange portion 58. The first seal holding groove 63 may be provided on the first mounting surface 56 a of the first flange portion 56. The second seal holding groove 64 may be provided in the cylinder head 25.

  As shown in FIG. 7, the inner surface of the second seal holding groove 64 has an annular inner peripheral portion 64a that surrounds the outlet 55 of the flow path 54, an annular outer peripheral portion 64c that surrounds the inner peripheral portion 64a, and an outer peripheral portion 64c. An annular bottom portion 64b that connects the inner peripheral portion 64a to each other, and one or more protruding portions 64d that protrude inward in the radial direction Dr from the outer peripheral portion 64c. The protruding portion 64d may be provided on both the inner peripheral portion 64a and the outer peripheral portion 64c, or may be provided only on the inner peripheral portion 64a. The width of the second seal holding groove 64 (the length in the radial direction Dr) decreases at a position corresponding to the protrusion 64d. The second seal 62 is prevented from dropping from the second seal holding groove 64 by the protrusion 64d.

  As shown in FIG. 5, the fuel injector 44 is inserted into an injector mounting hole 65 that opens at the outer wall 52 of the intake member 50. The injector mounting hole 65 is disposed at a height between the inlet 53 of the flow path 54 and the outlet 55 of the flow path 54. The injector mounting hole 65 extends from the outer wall 52 of the intake member 50 toward the inner wall 51 of the intake member 50 toward the outlet 55 of the flow path 54. The injector mounting hole 65 opens at an inner wall 51 of the intake member 50 (an inner wall of a second passage 68 described later). The injector mounting hole 65 is connected to the flow path 54.

  Although not shown, the fuel injector 44 includes a fuel injection port for spraying fuel, a valve for opening and closing the fuel injection port, an electric actuator for moving the valve between an open position and a closed position, a valve, and an electric actuator. And a housing for housing the housing. The housing of the fuel injector 44 is inserted into the injector mounting hole 65. The housing of the fuel injector 44 is fixed to the intake member 50 by a nut member 66 held by the intake member 50 and a bolt (not shown).

  As shown in FIG. 10, the flow path 54 of the intake member 50 includes a first passage 67 and a second passage 68 that are continuous with each other. Both the first passage 67 and the second passage 68 have an arc shape. The first passage 67 is disposed upstream of the second passage 68 in the intake air flow. The upstream end of the first passage 67 corresponds to the inlet 53 of the flow path 54, and the downstream end of the second passage 68 corresponds to the outlet 55 of the flow path 54. The diameter of the first passage 67 decreases as it approaches the downstream end of the first passage 67. On the other hand, the diameter of the second passage 68 decreases as the upstream end of the second passage 68 is approached. The diameter D1 (diameter of the inlet 53) at the upstream end of the first passage 67 is larger than the diameter D4 (diameter of the outlet 55) at the downstream end of the second passage 68. As shown in FIG. 11, the diameter D <b> 2 at the downstream end of the first passage 67 is smaller than the diameter D <b> 3 at the upstream end of the second passage 68.

  As shown in FIG. 10, the center line 70 of the intake member 50 includes a first arc portion 71 and a second arc portion 72 that are continuous with each other. The first arc portion 71 is a center line of the first passage 67, and the second arc portion 72 is a center line of the second passage 68. Each of the first arc portion 71 and the second arc portion 72 is an arc having a central angle of 90 degrees or less and a constant curvature radius. The first curvature radius 71 b of the first arc portion 71 is smaller than the second curvature radius 72 b of the second arc portion 72. The first curvature radius 71b may be equal to the second curvature radius 72b or may be larger than the second curvature radius 72b.

  FIG. 10 shows a cross section of the intake member 50 taken along line XX shown in FIG. Therefore, the first arc portion 71, the first curvature center 71a, the second arc portion 72, and the second curvature center 72a are all on the same plane. The first curvature center 71a of the first arc portion 71 and the second curvature center 72a of the second arc portion 72 are at different positions. A line segment X1 in which the first curvature center 71a and the second curvature center 72a are arranged at both ends intersects the center line 70 of the intake member 50. Furthermore, the intersection of the line segment X 1 and the center line 70 overlaps the intersection of the first arc portion 71 and the second arc portion 72. The first center of curvature 71 a and the second center of curvature 72 a are disposed opposite to the center line 70 of the intake member 50. Since the line segment X1 intersects the center line 70 of the intake member 50, the difference in the heat transfer distance can be reduced on the same plane.

  As shown in FIG. 10, the inner wall 51 of the intake member 50 forms an annular step 73 at the connection position of the first passage 67 and the second passage 68. FIG. 11 is a schematic diagram showing a cross section of the enlarged step 73. As shown in FIG. 11, the step 73 includes an annular upstream wall 74 extending in the axial direction Da of the intake member 50 and an annular downstream wall extending in the axial direction Da of the intake member 50 at a position downstream of the upstream wall 74. Part 76, and an annular connecting wall part 75 that connects the upstream wall part 74 and the downstream wall part 76 to each other.

  The upstream wall portion 74, the connection wall portion 75, and the downstream wall portion 76 all surround the center line 70 of the intake member 50. The upstream wall portion 74 and the downstream wall portion 76 extend along the center line 70 of the intake member 50, and the connection wall portion 75 extends in a direction intersecting with the center line 70 of the intake member 50. FIG. 11 shows an example in which the connection wall portion 75 is arranged on a plane orthogonal to the center line 70 of the intake member 50.

  As shown in FIG. 11, the connection wall portion 75 connects the first connection end 75 a of the upstream wall portion 74 and the second connection end 75 b of the downstream wall portion 76 to each other. The first connection end 75 a means an intersection line between the upstream wall portion 74 and the connection wall portion 75, and the second connection end 75 b means an intersection line between the downstream wall portion 76 and the connection wall portion 75. The first connection end 75 a corresponds to the downstream end of the first passage 67, and the second connection end 75 b corresponds to the upstream end of the second passage 68. The diameter D2 of the first connection end 75a is smaller than the diameter D3 of the second connection end 75b. The distance from the first connection end 75a to the second connection end 75b in the radial direction Dr of the intake member 50 (the width W1 of the connection wall portion 75) is the diameter D1 of the upstream end of the first passage 67 and the downstream of the first passage 67. It is smaller than the difference from the end diameter D2. When the first connection end 75a and the second connection end 75b are projected onto a plane orthogonal to the center line 70 of the intake member 50, the area of the region surrounded by the first connection end 75a is surrounded by the second connection end 75b. It is smaller than the area of the region.

Next, a method for manufacturing the intake member 50 will be described.
In the manufacturing process of the intake member 50, an injection molding machine is used. FIG. 12 shows a mold apparatus 81 attached to the injection molding machine. The mold device 81 includes a mold that molds the outer wall 52 of the intake member 50 and a core that molds the inner wall 51 of the intake member 50. As shown in FIG. 13, the mold includes a first mold 82 and a second mold 83 that form a cavity into which molten resin is injected. As shown in FIG. 12, the core includes an arc-shaped first rotating core 84 and a second rotating core 85 arranged in a cavity formed by the first mold 82 and the second mold 83. .

  As shown in FIG. 12, each of the first rotating core 84 and the second rotating core 85 has a cylindrical shape having an arc-shaped center line. The outer peripheral surface of the first rotating core 84 has a tapered shape in which the outer diameter decreases as it approaches the first end portion 84a corresponding to the tip portion. Similarly, the outer peripheral surface of the second rotating core 85 has a tapered shape in which the outer diameter decreases as it approaches the second end 85a corresponding to the tip. The first passage 67 of the intake member 50 is formed by the outer peripheral surface of the first rotating core 84, and the second passage 68 of the intake member 50 is formed by the outer peripheral surface of the second rotating core 85. The outer diameter of the first end portion 84a is smaller than the outer diameter of the second end portion 85a.

  As shown in FIG. 12, when molding the intake member 50, a part of the first rotating core 84 including the first end 84a and a part of the second rotating core 85 including the second end 85a. Are arranged in a cavity formed by the first mold 82 and the second mold 83. At this time, the cylindrical first end of the first rotating core 84 is such that the arc-shaped center line 86 of the first rotating core 84 and the arc-shaped center line 87 of the second rotating core 85 are continuous. The portion 84a and the cylindrical second end portion 85a of the second rotating core 85 are abutted against each other. The step 73 of the intake member 50 is formed by the first end portion 84a and the second end portion 85a.

  As shown in FIG. 12, the first rotating core 84 is connected to a first actuator 88 such as a hydraulic cylinder outside the first mold 82 and the second mold 83. The first actuator 88 rotates the first rotating core 84 around the center of curvature 86a of the center line 86 of the first rotating core 84, whereby the first end 84a is disposed in the cavity (see FIG. 12) and the first rotating core 84 is moved between the retracted position where the first end 84a is retracted from the cavity.

  As shown in FIG. 12, the second rotating core 85 is connected to a second actuator 89 such as a hydraulic cylinder outside the first mold 82 and the second mold 83. The second actuator 89 rotates the second rotating core 85 around the center of curvature 87a of the center line 87 of the second rotating core 85, thereby forming the second end 85a in the cavity (see FIG. 12) and the second end 85a is moved to the retracted position where the second end 85a is retracted from the cavity.

  When the intake member 50 is formed, the first mold 82 and the second mold 83 are overlapped and closed as shown in FIG. Further, as shown in FIG. 12, a part of the first rotating core 84 and the second rotating core 85 is disposed in the cavity formed by the first mold 82 and the second mold 83. As a result, the resin injection space 91 filled with the resin in the state where the first end portion 84a of the first rotating core 84 and the second end portion 85a of the second rotating core 85 are in contact with each other becomes the first gold. It is formed between the mold 82 and the second mold 83 and the first rotating core 84 and the second rotating core 85.

  After the first mold 82, the second mold 83, the first rotating core 84, and the second rotating core 85 are arranged in the respective molding positions, the molten resin is provided in the first mold 82. The resin is injected into the resin injection space 91 from the injection port 82a (see FIG. 13). Thereby, as shown in FIG. 14, liquid resin spreads over the resin injection space 91, and the resin injection space 91 is filled with resin. The first mold 82 and the second mold 83 are cooled by cooling water that flows inside the first mold 82 and the second mold 83. Therefore, the liquid resin in the resin injection space 91 is cooled by the first mold 82 and the second mold 83. Thereby, the resin in the resin injection space 91 is solidified, and the resin intake member 50 is molded.

  After the resin in the resin injection space 91 is solidified, as shown in FIG. 15, the first rotary core 84 is rotated from the molding position to the retracted position by the first actuator 88. On the other hand, the second rotating core 85 is rotated from the molding position to the retracted position by the second actuator 89. As a result, the first end 84 a of the first rotating core 84 and the second end 85 a of the second rotating core 85 are separated from each other and are disposed outside the first mold 82 and the second mold 83. . Therefore, the first rotating core 84 and the second rotating core 85 are removed from the intake member 50 in the first mold 82 and the second mold 83.

  After the first rotating core 84 and the second rotating core 85 are removed from the intake member 50, the second mold 83 is moved to the retracted position, and the first mold 82 and the second mold 83 are opened. As a result, the intake member 50 is separated from the first mold 82 and remains in the second mold 83. Thereafter, the suction member 50 is removed from the second mold 83 manually or automatically. If necessary, after the intake member 50 is removed from the mold device 81, machining such as cutting is performed on the intake member 50. In this case, the intake member 50 removed from the mold apparatus 81 corresponds to an intermediate body of the intake member 50.

  As described above, in the first embodiment, since the intake member 50 is made of a resin having a lower thermal conductivity than metal, it is difficult for the heat of the engine 8 to be transmitted to the intake flow rate adjustment device 38 via the intake member 50. Further, since the center line 70 of the intake member 50 includes the first arc portion 71 and the second arc portion 72, the heat transfer distance of the intake member 50 is greater than when the entire center line 70 of the intake member 50 is a straight line. Is big. Thus, since the heat conductivity of the intake member 50 is low and the heat transfer distance of the intake member 50 is large, the amount of heat transferred from the engine 8 to the intake flow rate adjusting device 38 can be further reduced. Therefore, the temperature rise of electronic components such as the throttle opening sensor 48 can be suppressed.

  Furthermore, since the center line 70 of the intake member 50 includes a plurality of arc portions (first arc portion 71 and second arc portion 72), the center line 70 of the intake member 50 includes only one arc portion. It is easy to adjust the position of the outlet 55 of the intake member 50 with respect to the inlet 53 of the intake member 50. That is, when the entire center line 70 of the intake member 50 is a circular arc, the inlet 53 and the outlet 55 of the intake member 50 are arranged on the same circumference, so the arrangement of the inlet 53 and the outlet 55 is restricted. Therefore, it is possible to secure the degree of freedom of the layout of the inlet 53 and the outlet 55 of the intake member 50 while reducing the amount of heat transfer to the intake flow rate adjusting device 38.

In the first embodiment, at least part of the outlet 55 of the intake member 50 can be seen from the inlet 53 of the intake member 50 even though the flow path 54 of the intake member 50 is curved. That is, the amount of heat transfer can be reduced even with a simple shape or a relatively short shape in which at least a part of the outlet 55 can be seen.
In the first embodiment, the first seal 61 and the second seal 62 are made of an elastic material having a lower thermal conductivity than metal. The first seal 61 is interposed between the intake flow rate adjusting device 38 and the intake member 50, and the second seal 62 is interposed between the engine 8 and the intake member 50. Therefore, the amount of heat transferred from the engine 8 to the intake flow rate adjustment device 38 can be further reduced. In addition, the gap between the engine 8 and the intake flow rate adjusting device 38 and the intake member 50 can be reliably sealed with the first seal 61 and the second seal 62.

  In the first embodiment, an annular step 73 is formed on the inner wall 51 of the intake member 50. The connection wall portion 75 connects the first connection end 75a of the upstream wall portion 74 and the second connection end 75b of the downstream wall portion 76 to each other. The second connection end 75b of the downstream wall portion 76 is disposed outside the first connection end 75a of the upstream wall portion 74 in the radial direction Dr of the intake member 50 at any position in the circumferential direction Dc of the intake member 50. Has been. The connection wall portion 75 faces downstream of the intake air flow.

  When the connecting wall 75 is directed upstream of the flow of intake air, the fuel contained in the air-fuel mixture flowing back to the intake member 50 due to the pulsation of the engine 8 gradually accumulates in the step 73 of the intake member 50 and accumulates in the step 73. Fuel droplets are sucked into the engine 8 at an unexpected timing. In this case, more fuel than the intended amount is supplied to the engine 8. Therefore, the amount of fuel staying in the intake member 50 can be reduced by directing the connection wall portion 75 to the upstream over the entire circumference.

  In the first embodiment, an air-cooled four-stroke single cylinder engine is used as the engine 8. Air-cooled engines are more likely to rise in temperature than water-cooled engines. Further, if the displacement is the same, the single cylinder engine is often smaller and has a smaller heat radiation area than the multi-cylinder engine. Therefore, when generating the same output, the temperature of the single cylinder engine is more likely to rise than that of the multi-cylinder engine. By attaching the intake member 50 according to the first embodiment to such an engine 8, the amount of heat transfer from the engine 8 to the intake flow rate adjusting device 38 can be effectively reduced.

Other Embodiments Although the description of the embodiment of the present invention has been described above, the present invention is not limited to the contents of the above-described embodiment, and various modifications can be made within the scope of the present invention.
For example, in the above embodiment, the case where the inner wall 51 of the intake member 50 has the step 73 has been described. However, the inner wall 51 of the intake member 50 may not have the step 73. In this case, the step 73 formed at the time of injection molding may be removed by machining such as shot peening, or the dimensions of the core may be adjusted so that the step 73 is not formed at the time of injection molding.

In the embodiment, the case where the opening area of the inlet 53 of the intake member 50 is smaller than the opening area of the outlet 55 of the intake member 50 has been described. However, the opening area of the inlet 53 may be equal to the opening area of the outlet 55 or may be larger than the opening area of the outlet 55.
In the embodiment, the case where the first arc portion 71, the first curvature center 71a, the second arc portion 72, and the second curvature center 72a are all on the same plane has been described. However, as shown in FIGS. 16 and 17, the first arc portion 71 and the first curvature center 71a are arranged on a plane S1 different from the plane S2 including the second arc portion 72 and the second curvature center 72a. May be. In this case, the first arc portion 71 and the second arc portion 72 are in a positional relationship twisted around a straight line L1 passing through the intersection of the first arc portion 71 and the second arc portion 72.

  In the embodiment, the line segment X1 in which the first curvature center 71a and the second curvature center 72a are arranged at both ends intersects the center line 70 of the intake member 50, and the line segment X1 and the center line of the intake member 50 The case where the intersection with 70 overlaps the intersection between the first arc portion 71 and the second arc portion 72 has been described. However, like the intake member 350 shown in FIG. 18, the line segment X <b> 1 does not need to intersect the center line 70 of the intake member 50. The line segment X1 and the center line 70 may overlap so that the intersection of the line segment X1 and the center line 70 does not overlap the intersection of the first arc part 71 and the second arc part 72.

In the above-described embodiment, the case where a part of the outlet 55 of the intake member 50 is visible when the inlet 53 of the intake member 50 is viewed from the intake flow rate adjusting device 38 has been described. However, when the inlet 53 is viewed in this way, the entire outlet 55 may be visible, or any part of the outlet 55 may not be visible.
In the embodiment, the case where the two flange portions (the first flange portion 56 and the second flange portion 58) are provided in the intake member 50 has been described. However, at least one of the two flange portions may be omitted.

  In the embodiment, the case where the intake member 50 is attached to the throttle body 40 and the cylinder head 25 via other members such as the first seal 61 and the second seal 62 has been described. However, the intake member 50 may be directly attached to the throttle body 40. Similarly, the intake member 50 may be directly attached to the cylinder head 25.

In the embodiment, the case where both the first seal 61 and the second seal 62 are annular seals has been described. However, at least one of the first seal 61 and the second seal 62 may be plate-shaped. That is, the first seal 61 and the second seal 62 are not limited to O-rings and may be gaskets.
The intake member 50 may be manufactured by a method other than the manufacturing method according to the embodiment.

In the embodiment, the case where the fuel supply device 43 includes the fuel injector 44 has been described. However, as shown in FIG. 19, the fuel supply device 43 may include a carburetor 394 instead of the fuel injector 44. In this case, it is not necessary to provide the injector mounting hole 65 in the intake member 50.
In the above embodiment, the case where the engine 8 is an air-cooled four-stroke single cylinder engine has been described. However, the engine 8 may be a water-cooled engine or a multi-cylinder engine. When the engine 8 is a multi-cylinder engine, a plurality of intake members 50 independent from each other may be provided in the saddle riding type vehicle 1, or an integrated member including the plurality of intake members 50 is provided in the saddle riding type vehicle 1. May be.

  In the embodiment, the case where the saddle riding type vehicle 1 is an underbone type motorcycle has been described. However, the saddle riding type vehicle 1 may be a scooter type motorcycle in which the engine 8 can swing in the vertical direction with respect to the frame 2, or may be a sports type motorcycle. The straddle-type vehicle 1 is not limited to a motorcycle, and may be a straddle-type vehicle having three or more wheels, or may be a rough terrain vehicle (ALL-TERRAIN VEHICLE). However, it may be a snowmobile.

  Two or more of all the embodiments described above may be combined.

1: Saddle-type vehicle 8: Engine 38: Intake flow rate adjusting device 50: Intake member 51: Inner wall 52: Outer wall 53: Inlet 54: Channel 55: Outlet 56: First flange portion 58: Second flange portion 61: First 1 seal 62: 2nd seal 67: 1st channel | path 68: 2nd channel | path 70: Centerline 71: 1st circular arc part 71a: 1st curvature center 71b: 1st curvature radius 72: 2nd circular arc part 72a: 2nd curvature Center 72b: second curvature radius 73: step 74: upstream wall 75: connection wall 75a: first connection end 75b: second connection end 76: downstream wall 82: first mold 83: second mold 84 : First rotating core 84a: first end 85: second rotating core 85a: second end 91: resin injection space 350: intake member Da: axial direction Dc: circumferential direction Dr: radial direction

Claims (13)

Engine,
An intake flow rate adjusting device for adjusting the flow rate of intake air sucked into the engine;
A resin intake member including an inner wall that forms a flow path for guiding intake air from the intake air flow adjusting device to the engine;
The center line of the intake member includes a first arc portion and a second arc portion that are continuous with each other,
The straddle-type vehicle, wherein a first curvature center of the first arc portion and a second curvature center of the second arc portion are at different positions.   The straddle-type vehicle according to claim 1, wherein all of the first arc portion, the first center of curvature, the second arc portion, and the second center of curvature are on the same plane.   The straddle-type vehicle according to claim 2, wherein a line segment in which the first curvature center and the second curvature center are arranged at both ends intersects a center line of the intake member.   The straddle-type vehicle according to claim 2, wherein a line segment in which the first curvature center and the second curvature center are arranged at both ends does not intersect a center line of the intake member.   The straddle-type vehicle according to claim 1, wherein the first arc portion and the first center of curvature are arranged on a plane different from a plane including the second arc portion and the second center of curvature.   The straddle-type vehicle according to any one of claims 1 to 5, wherein a curvature radius of the first arc portion and a curvature radius of the second arc portion are different from each other. The intake member includes an outer wall formed with an inlet for guiding the intake air that has passed through the intake air flow adjusting device to the flow path, and an outlet for discharging the intake air that has flowed into the inlet.
The straddle-type vehicle according to any one of claims 1 to 6, wherein when the inlet is viewed from the intake flow rate adjusting device, at least a part of the outlet is visible.   The straddle-type vehicle according to any one of claims 1 to 7, wherein the intake member further includes a flange formed at an end of the flow path.   The straddle-type vehicle according to any one of claims 1 to 7, further comprising a seal made of an elastic material interposed between the engine or the intake air flow adjusting device and the intake member. The inner wall of the intake member includes an upstream wall portion extending in the axial direction of the intake member, a downstream wall portion extending in the axial direction of the intake member at a position downstream of the upstream wall portion in the flow of intake air, and the upstream An annular step including a first connecting end of the wall portion and a connecting wall portion connecting the second connecting end of the downstream wall portion to each other is formed,
The second connection end of the downstream wall portion is disposed outward from the first connection end of the upstream wall portion in the radial direction of the intake member, and the connection wall portion is formed of the first connection end. The straddle-type vehicle according to any one of claims 1 to 9, wherein the saddle-type vehicle extends outward in a radial direction of the intake member from the first end toward the second connection end.   The straddle-type vehicle according to any one of claims 1 to 10, wherein the engine is an air-cooled engine.   The straddle-type vehicle according to any one of claims 1 to 11, wherein the engine is a single cylinder engine. A method of manufacturing the air intake member for manufacturing an air intake member made of resin including an inner wall that forms a flow path that guides intake air to the engine from an air intake flow rate adjusting device that adjusts a flow rate of intake air sucked into the engine,
In a state where the first end portion of the arc-shaped first rotating core and the second end portion of the arc-shaped second rotating core are abutted with each other, the mold, the first rotating core and the second rotating core, Forming a resin injection space between
Injecting resin into the resin injection space to mold the intake member;
Removing the first rotating core and the second rotating core from the intake member by rotating the first rotating core and the second rotating core.

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